An example of an Open DRM application, might be to manufacture a batch of digital movie projectors, that decrypt with unique RSA private keys.
The use of the device, would be for the Studio to encipher the same movie uniquely for each projector. If it lasted for fully five weeks, it would be adequate for first run projection.
As a practical matter, it would be important to make the key “tamper evident” to reverse engineering. Since computer chips are quite hard to reverse engineer, a gate array password scheme appears to be a good idea. Since RSA is a stream cipher, it would be hard to steal excerpts.
This scheme would differ from a Container type scheme, because a container must be mounted to employ it. A mounted container is analogous to an unencrypted file, or partition. A stream encrypted data stream from a BD-R or DVD-R, would be encrypted right up until the gate array.
All efforts to defeat the scheme would center on recording the output between the gate array and the actual silver screen.